Problems in the operation of tumbler dryers often arise by reason of items left in the pockets of clothes or other garments being laundered. Users of laundry machines in coin operated laundries frequently do not clean out pockets of the clothing and dry wall screws and nails inadvertently left in the pockets during laundering can work their way free and migrate to the outer wall of the rotating tumbler drum or basket by reason of centrifugal forces. Such dry wall screws and nails quickly find their way through one of the many airflow holes in the perforated tumbler basket with the heads of the fasteners, which are larger than the tumbler basket openings, retaining the screws in outwardly protruding relation to the tumbler basket such that continued rotation of the tumbler under the power of the laundry machine drive motor causes these screws to gouge and cut a circular ring in the tumbler. The resulting damage is very expensive and time consuming to repair. Dry wall screws and nails are particularly troublesome since the thread-like ridges in the shank of the fastener tend to resist dislodgement of the screw from the tumbler opening when engaging the surrounding dryer panels. Moreover, upon tearing an opening in the surrounding dryer panel ambient air is permitted to enter the tumbler from the torn opening, rather than from the heated air inlet, which in turn can lead to overheating at the inlet of the dryer and the potential for fire.
Proposals to make airflow openings in the dryer tumbler larger to permit free passage of the dry wall screw heads have proven unsuccessful. If the airflow holes of the tumbler are made sufficiently large to permit passage of drywall screws, buttons on garments being dried, and particularly relatively small collar buttons, also can pass through the airflow openings and become trapped in the airflow opening, causing rippage and damage to the clothing. In fact, the tumblers of dryers typically have a standard airflow hole size of 0.312 inches, which is slightly smaller than the diameter of the common shirt collar button. Due to such relatively small airflow openings, tumblers must be manufactured with a high density of such openings to permit adequate airflow during operation of the dryer. Malfunction detection systems, such as shown in U.S. application Ser. No. 10/875,002 filed Jun. 22, 2004, for monitoring and shutting down operation of the dryer in the event of such protruding dry wall screws are relatively complicated and expensive.